Important Motion Control Concepts
The term "motion control" is used herein to refer to the process by which a mechanism is moved in a known manner. For example, a tape recorder employs motion control to pull the tape slowly over the "record" and "playback" heads and also to rewind the tape rapidly. The object of such motion control may be to move an object at a known speed or to move the object through a known distance. For example, the tape player must pull the tape across the playback head at a known speed in order that the sound be reproduced faithfully. However, when the tape is being rewound, the constancy of the tension of the tape is of more importance than the constancy of the speed of the tape.
Motion control is used in many industrial processes. Thus, assembly lines and conveyors move at known speeds; plastics and steel are formed as moving sheets; textiles are spun and wound by moving equipment; and robots grasp and move parts by the coordinated action of several motors.